Scubapro Flux Twin Zoom / Evo Mask Optical Lenses If you dive with a SCUBAPRO Flux Twin or Zoom EVO mask and need some optical enhancement, you\'re in luck. A wide selection of optical lenses are available. Features: Find the ideal diopter lens to enhance your underwater view Lens choices range from -1.0 to -8.0 in .5 diopter increments Lenses are interchangeable and will fit the left or right side Optical lenses make sure you get the absolute cleanest and clearest view of the underwater world